Preparation

Make ginger syrup:
Bring water, sugar, and ginger to a boil in a 1- to 1 1/2-quart saucepan, stirring until sugar is dissolved. Simmer, uncovered, stirring occasionally, 10 minutes, then remove from heat and steep, uncovered, 15 minutes. Pour syrup through a sieve into a bowl, discarding ginger. Chill, covered, until cold, about 2 hours.

Make punch:
Stir together ginger syrup and fruit juices in a punch bowl or pitcher. Stir in sparkling water and ice.